A typical gripper usable as a tool chuck or pallet loc has a body holding an actuating element that can be moved by an electric actuator between a holding position and a release position so as to operate a segment collet having at least two collet jaws. These jaws can grip a pin forming the stem or shank of a tool or a pull-down bolt of a pallet.
In a pallet-locking system a plurality of these grippers interact with respective mounting bolts on the pallet and clamp them in place. One problem that can nevertheless arise here is that the pallet can no longer be removed from the locking system if there is a failure of the electric actuator for a single gripper. As a result, this type of failure often necessitates destroying the pallet in order to be able to separate it from the locking system and replace the defective actuated gripper.
The same problem also occurs when instead of the mounting bolt it is a tool that is gripped in a chuck. Here again the problem is that a failure of the electric actuator means that the tool can no longer be removed from the chuck. This then results in an increase in cost and possibly down times in production due to time-consuming maintenance work.